The present invention relates generally to the field of communication, and, more particularly, to cellular communication systems that use a paging channel, which a mobile terminal can monitor to check for incoming calls.
Wireless or cellular communication systems are commonly used to provide voice and data communication services to subscribers. A typical terrestrial cellular radiotelephone communication system 20 is illustrated in FIG. 1. The cellular radiotelephone system 20 may include one or more mobile terminals or radiotelephones 22a,b,c, that communicate via a plurality of cells 24a,b,c served by base stations 26a,b,c and a mobile switching center (MSC) 28. Although only three cells 24a,b,c are shown, a typical cellular network may include hundreds of cells, multiple MSCs 28, and may serve thousands of mobile terminals 22a,b,c. 
The cells 24a,b,c generally serve as nodes in the communication system 20 from which links are established between the mobile terminals 22a,b,c and the MSC 28 by way of the base stations 26a,b,c serving the cells 24a,b,c. Each cell 24a,b,c will typically have allocated to it one or more dedicated control channels and one or more traffic channels. A control channel is a dedicated channel used for transmitting such things as cell identification and paging information. A traffic channel carries the voice and data information. A duplex radio communication link may be established through the cellular network 20 between two mobile terminals 22a,b,c or between a mobile terminal 22a,b,c and a wireline telephone user 32 through the public switched telephone network (PSTN) 34. A function of the base stations 26a,b,c is to handle radio communication between the cells 24a,b,c and the mobile terminals 22a,b,c. In this capacity, the base stations 26a,b,c may function as a relay station for data and voice signals.
As discussed in the foregoing, mobile terminals 22a,b,c may obtain paging information from a base station 26a,b,c over a control channel, which is typically referred to as a paging channel. A base station 26a,b,c will transmit a page to a mobile terminal 22a,b,c to notify the mobile terminal 22a,b,c that it has an incoming call. To conserve battery resources, a mobile terminal 22a,b,c will generally not monitor the paging channel continuously, but will instead check for an incoming page on a periodic basis. Accordingly, the paging channel is generally divided into time slots or time intervals and a mobile terminal 22a,b,c will periodically monitor the paging channel during specific time intervals to check for an incoming page. The frequency with which a mobile terminal 22a,b,c monitors the paging channel is typically controlled by a parameter called the slot cycle index (SCI).
The SCI parameter may be used to control when a mobile terminal 22a,b,c xe2x80x9csleepsxe2x80x9d and when a mobile terminal 22a,b,c xe2x80x9cwakes upxe2x80x9d to check for incoming calls. For example, if the SCI parameter is set to one, then a mobile terminal 22a,b,c will monitor every time slot or time interval of the paging channel to check for an incoming call. While this SCI setting may provide the best responsiveness to incoming calls, it may also prematurely expend battery resources. If the SCI parameter is set to two, then a mobile terminal 22a,b,c will monitor every other time slot. Similarly, if the SCI parameter is set to three, then a mobile terminal 22a,b,c will monitor every third time slot. By setting the SCI parameter to a higher number, a mobile terminal 22a,b,c will spend a higher percentage of its time xe2x80x9csleepingxe2x80x9d and, thus, conserve battery power. This conservation of battery resources, however, comes at the expense of diminished responsiveness to incoming calls. Moreover, if the SCI parameter is set too high, then a landline caller may hang-up prematurely because of the lengthy delay before the mobile terminal 22a,b,c detects the page associated with the incoming call and begins to ring.
A mobile phone user may program a desired SCI parameter, but the service provider typically sets it to a single, constant value. Generally, this value is set to provide a suitable balance between battery life and responsiveness to incoming calls. Nevertheless, this single SCI setting may not be desirable in all operating environments or scenarios.
A paging channel may be monitored for incoming calls to a mobile terminal by determining a current operating environment of the mobile terminal and then adjusting the paging channel monitoring frequency based on the current operating environment. The present invention stems from the realization that decreased power consumption may be preferred to improved responsiveness to incoming calls in some operating environments while improved responsiveness to incoming calls may be preferred to decreased power consumption in other operating environments. Advantageously, a mobile terminal, in accordance with the present invention, may dynamically balance responsiveness to incoming calls with power consumption in accordance with its operating environment rather than being limited to a static or semi-static balance between the two performance criteria.
In accordance with an aspect of the invention, user input may be obtained to associate operating environments with corresponding paging channel monitoring frequencies. In particular, a user may be presented with a menu containing a list of operating modes for the mobile terminal with each operating mode being associated with an operating environment. Exemplary operating modes may include, but are not limited to, an external power performance mode, a time of day performance mode, an enhanced performance environment mode, and a usage pattern performance mode.
The external power performance mode is associated with an operating environment in which an external power supply is connected to the mobile terminal. In this operating environment, it is generally desirable to increase the paging channel monitoring frequency as power conservation is not a concern. The time of day performance mode is associated with an operating environment in which local times have been programmed by a user that identify extended sleep cycle intervals in which it is desirable decrease the paging channel monitoring frequency to conserve power and enhanced responsiveness sleep cycle intervals in which it is desirable to increase the paging channel monitoring frequency to provide improved responsiveness to incoming calls. The enhanced performance environment mode is associated with an operating environment in which it is desirable to increase the paging channel monitoring frequency because call traffic in this operating environment is frequently above average. Examples of enhanced performance operating environments may include a home base station, a wireless local loop system, or a private campus system. Finally, the usage pattern performance mode is associated with an operating environment in which the mobile terminal collects incoming call statistics for the mobile terminal and, based on these statistics, defines times for extended sleep cycles and/or enhanced responsiveness sleep cycles.
In accordance with another aspect of the invention, the paging channel monitoring frequency may be adjusted by adjusting the value of the slot cycle index (SCI) parameter and then transmitting the SCI parameter value to a base station.
Thus, the present invention may allow a user to program their mobile terminal to provide a level of responsiveness to incoming calls that is tailored to their individual preference.